<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/mediaqueries-5/#prefers-reduced-transparency" />
<script type="text/javascript" src="/resources/testharness.js"></script>
<script type="text/javascript" src="/resources/testharnessreport.js"></script>

<script type="text/javascript" src="resources/matchmedia-utils.js"></script>
<script>
query_should_be_known("(prefers-reduced-transparency)");
query_should_be_known("(prefers-reduced-transparency: no-preference)");
query_should_be_known("(prefers-reduced-transparency: reduce)");

query_should_be_unknown("(prefers-reduced-transparency: 0)");
query_should_be_unknown("(prefers-reduced-transparency: none)");
query_should_be_unknown("(prefers-reduced-transparency: 10px)");
query_should_be_unknown("(prefers-reduced-transparency: no-preference reduce)");
query_should_be_unknown("(prefers-reduced-transparency: reduced)");
query_should_be_unknown("(prefers-reduced-transparency: no-preference/reduce)");

test(() => {
  // https://drafts.csswg.org/mediaqueries-5/#boolean-context
  let booleanContext = window.matchMedia("(prefers-reduced-transparency)");
  let noPreference = window.matchMedia("(prefers-reduced-transparency: no-preference)");
  assert_equals(booleanContext.matches, !noPreference.matches);
}, "Check that no-preference evaluates to false in the boolean context");

test(() => {
  let invalid = window.matchMedia("(prefers-reduced-transparency: 10px)");
  assert_equals(invalid.matches, false);
}, "Check that invalid evaluates to false");
</script>